Reference Mix Research Articles

The synergic effect of polyethylene fibres and CNT on the properties of ultralightweight cementitious composites

This paper presents an experimental investigation utilizing ordinary Portland cement (OPC), carbon nanotube (CNT), metakaolin (MK) and 1.75% polyethylene (PE) fibres to develop a high performance CNT and fibre-reinforced ultra-lightweight cementitious composites (ULCC). Ultra-low density was achieved by using cenospheres. The effects of different dosages of CNT, different types of binders and PE fibres were investigated. The workability, hardened properties (density, compressive strength and flexural strength), sorptivity, microstructure and cost of each mix were also investigated. From this experiment, PE and CNT-reinforced high-strength ULCC with a dry density of around 1500 kg/m3, compressive strength of around 87 MPa and flexural strength of around 18 MPa with flexural hardening can be produced. The effect of CNT and the synergic effect of CNT and PE fibres were investigated and discussed. The synergic effect of CNT was better than the combination of the separate effects of CNT and PE fibres. Compared to the reference mix MRF, when combined with 1.75% PE fibres, 0.2%, 0.4%, 0.6% CNT can improve 260%, 276% and 239% of flexural strength, increase by 35.6%, 61% and 58.5% of compressive strength, 4.5%, 29% and 21.3% for specific strength. It was found that the cost of each mix increases by around 1067 AUD per cubic meter by the increase of 0.2% CNT in each mix. Finally, from multi-criteria analysis, M0.4CNTPE was recommended in this study.

Laboratory and Field Testbed Evaluation of the Performance of Recycled Asphalt Mixture Using High-Penetration Asphalt

The application of recycled asphalt pavement (RAP) on a large scale is highly promoted to meet the current needs of carbon neutrality and sustainable development purposes. However, a majority of RAP mixture productions are currently relying on the restoring effects provided by the rejuvenators. Therefore, the study focuses on the feasibility of using high penetration asphalt binder (HPAB) in RAP mixture as a replacement for conventional rejuvenators. In this study, a recycled asphalt pavement mixture containing HPAB (RAP-H) was developed to resolve the cracking issue of RAP pavement in winter seasons owing to the rigid behavior of aged binders. To verify the applicability of the RAP-H mixture, the results of the quality standard test and mechanical performance test were compared with the reference RAP mixture having rejuvenator (RAP-R). Through the fatigue cracking test, by using Overlay Tester (OT) device, it was found that all specimens did not reach 93% load reduction after 1000 OT cycles, indicating a satisfied stress-bearing capacity. Additionally, the highest dynamic modulus of 27,275 MPa was found in the modified HPAB mixture, and this result is 4.4% higher than that of the reference mix. In the full-scale testbed, the long-term field applicability of the proposed approach was verified through field test construction. The measurement in practice reveals that the elastic modulus of RAP-H back-calculated from the FWD (Falling Weight Deflectometer) test is increased by more than 50% compared to RAP-R, which resulted in excellent performance characteristics of the HPAB pavement layer. In addition to the efficiency in the surface layer, an improved elastic modulus of the sub-base and subgrade layers in the HPAB section was found to be at 28.6% and 19.5%, respectively, compared to the RAP-R mix. In general, the performance of RAP-H satisfied all of the domestic and international quality and performance standards. The field test results confirmed the possibility of field application by showing performance higher than conventional recycled asphalt pavement.

Utilization of hybrid fibers in different types of concrete and their activity

Abstract In this work, the influence of using hybrid fibers on the mechanical properties of two types of concrete: high-strength concrete (HSC) and lightweight concrete (LWC) was studied. Using hybrid fibers instead of using only one type reduced the negative effect on concrete mechanical performance. The glass fiber (GF) and polypropylene fiber (PPF) were used in different contents ranged from 0.2 to 1% as weight % of binder content. Moreover, combinations of both fibers “GF + PPF” were used in contents % of “0.3 + 0.5%,” “0.5 + 0.5%,” “0.3 + 1%,” and “0.5 + 1%.” LWC mixes were prepared by replacing 40% of the coarse aggregate of reference mix with volcanic material (pumice) as a volumetric replacing. To produce HSC, the water-to-cement ratio was reduced to 0.3, 10% silica fume was added, and 1% super plasticizer was used to obtain the consistency. Compressive strength, splitting strength, and flexural strength tests were carried out. The results showed that using 0.7% GF displayed the highest increases in compressive, splitting tensile, and flexural strength of HSC and LWC mixes. Furthermore, GF exhibited better performance and higher values in compressive, splitting tensile, and flexural strength tests in comparison with PPF. The optimum hybrid fiber content displaying the highest increment of all tested properties in both concrete types, HSC and LWC, was “0.5% GF + 0.5% PPF.”

Studying Thermal and Mechanical Properties of Recycled Concrete by Using Ceramic Aggregate

Ceramic aggregate has the characteristics of light weight, heat insulation, and low cost, and recycled aggregate is a type of green material that realizes the re-crushing of construction waste. This paper studied the impact of replacing natural coarse aggregate with ceramic aggregate and natural sand with recycled fine aggregate, on the physical, mechanical, and thermal properties of concrete. Recycled fine aggregate was used to completely replace natural sand. A total of five concrete mixes (including a reference mix) were prepared with different levels of ceramic aggregate (0%, 30%, 50%, 70%, 100%). Density, compressive strength, thermal conductivity, and thermal inertia index were measured to evaluate the performance of each mixture, and ceramic concrete board and hollow blocks were designed for testing the thermal properties. Results of testing show that density, strength, and thermal performance are interrelated. The smaller the density, the lower the strength, and it indicates that ceramic aggregate has a negative influence on strength in concrete. Meanwhile, the smaller the density, the higher the thermal resistance, and the addition of ceramic aggregate can improve the thermal insulation of concrete. The mechanical and thermal properties are both affected by the ceramic replacement ratio. Ceramic aggregate improves the thermal properties of recycled concrete, and the negative influence of ceramic aggregate on compressive strength can be controlled by the replacement ratio of aggregate in concrete. Based on the overall comparison and analysis, a mix with 50% ceramic aggregate shows relatively better strength and thermal insulation compared to other mixes. The use of ceramic aggregate in combination with recycled fine aggregate can effectively reduce the environmental pollution and make an economical substitute for their natural counterparts.

Properties of Sustainable Concrete Utilization Foundry Sand

The reduction of natural sand used in concrete as fine aggregate due to widely concrete usage has led to search for another alternative to sand. The effect of using foundry sand waste to partially replaced sand by weight in concrete has been studied in this paper. Percentages (10%, 20%, 30%, and 40%) of waste foundry sand have been used and the results of workability, dry density, water absorption, compressive strength, split tensile and flexural strength with reference concrete mix that contain natural sand 100% have been compared. The chemical and the physical properties of foundry sand have been examined. Substitute waste foundry sand up to 30% has decreased workability and has increased the density. The 30% replacement has recorded the more increase in compressive and splitting strength of about 25.6% and 17.2% respectively for age 7 days, while 10.7% and 15.6% respectively at age 28 days. Waste foundry sand has been less effective in enhancing the flexural strength than compressive strength. The 40% replacement has showed poor results. The effect of superplasticizer has been studied on 40% waste foundry sand mix. Using superplasticizer 1% of cement weight has recorded increase in compressive and splitting strength of about 9.9% and 4.4% respectively for age 7 days, while 2.8% and 9% % respectively at age 28 days when compared to the reference mix.

High-strain rate compressive behavior of concrete with two different substituted recycled plastic aggregates: Experimental characterization and probabilistic modeling

This paper presents a pilot study on the characterization of the high-strain rate compressive behavior of a novel concrete with two different substituted recycled plastic aggregates. A reference mix with an average compressive strength of about 55MPa is considered. Recycled PolyEthylene Terephthalate (PET) powder and recycled mixed plastic (composed of PolyPropylene (PP) and PolyEthylene (PE)) granules were adopted to substitute fine and coarse aggregates. Two different substitution strategies are employed. In the first one, the PET powder is used to substitute the fine sand by volume. In the second one, the PET powder is used to substitute the fine sand while the recycled mixed plastic granules are used to substitute the coarse sand and fine coarse aggregates by volume (50% for PET powder and 50% for recycled mixed plastic granules). Four total replacement levels (5%, 10%, 20%, and 30%) by volume were considered. The fresh concrete properties (slump and density) and quasi-static compressive behavior, are investigated. The micro-scale characterization of the material using SEM scans provided a complete understanding of the observed macro-scale behavior. Tests were performed using conventional quasi-static loading with a compressive testing machine and high-strain rate tests with a Φ80-mm Split-Hopkinson Pressure Bar (SHPB) for strain rates up to 200s−1. The dynamic tests revealed the marked strain rate dependency, although specimens with large plastic volume substitution were more sensitive to the strain rate effect. A probabilistic data-driven model for the Dynamic Increase Factor (DIF) is also proposed based on the test data. Ultimately, this study indicates that the proposed material has a good high-strain rate compressive behavior and can be a promising material to be employed for protective techniques against impact and blast loads.

Self-compacting concrete strengthening efficiency investigation using recycled steel waste as fibres

Steel recycling saves energy and time, and is more environmentally friendly. It can help rid the environment of huge amounts of scrap vehicles and huge structures, as well as reducing the mining operations that destroy the natural environment. In this investigation, the steel scrap effect on the mechanical properties of concrete was investigated, in addition to investigating the variation in mechanical properties with increased concrete age. Three concrete mixes were studied: one without steel waste as a control, one with 1% steel waste by volume of concrete, and one with 1.5% steel waste by volume of concrete. The results show that adding waste steel to the concrete improved the compressive strength as well as the tensile strength, where a mixture which contains 1% of steel waste had an increase in strength of up to 12% and 23% by day 28 for compressive strength, and tensile strength sequentially in comparison to the reference mix. Furthermore, the results show that there was a significant increase in splitting tensile strength, at 29% on day 28 for a mix of 1.5% steel waste as compared to the reference concrete mix. The best improvement in compressive strength over time was obtained when using 1% steel waste. The best improvement in tensile strength over time was obtained when using 1.5% of steel waste. In both cases, the amount of the improvement was better than the models without steel waste, which gives us confidence in giving recommendations for conducting more in-depth studies to achieve the maximum advantage.

The influence of sepiolite on the self-healing capability of concrete by means of water permeability

This paper investigates the autogenous self-healing capability of conventional concrete (C30/37) mixtures with water encapsulated in sepiolite. Sepiolite was added in two conditions: previously saturated and dry, at a dosage of 5% by the cement weight. Sepiolite is added in substitution for the sand fraction. For these two mixes and a reference mix without sepiolite, disks of size f100x50 mm were produced and were pre-cracked at 28 days of age by splitting test until reaching residual cracks of 300±150 μm. Crack width was measured by using an optical microscope. Self-healing was promoted after pre-cracking in certain exposures: 1) continuous water immersion at 20°C for 56 days, 2) a high humidity environment at 20°C and 95% of relative humidity for 28 days and water immersion for additional 28 days, and 3) pre-saturation for one day and 55 days in a humidity chamber. Self-healing was analyzed with water permeability by comparing the results before and after the healing stage. Afterward, chlorides’ penetration through the healed cracks was evaluated to study the possible protection provided by crack healing. Uncracked specimens were also tested as a reference for chloride penetration. Mixes were characterized by measuring compression strength at 28 days, slump, air content, and fresh density. The results show that water immersion is an adequate way to improve autogenous self-healing. Sepiolite can improve the self-healing capability of concrete with only one day of pre-saturation and then healing in high humidity conditions, especially in mixes with sepiolite introduced in saturated conditions. On the contrary, sepiolite may have resulted in a higher chloride penetration compared to samples without sepiolite.

Effect of magnetic water and neem leaves ash on strength properties

The present research work concentrates on utilization of neem leaves ash as a SCM material by blending in concrete. M20 mix design was considered as a reference mix. Neem leaves ash was replaced to cement with varying percentages 0.0 %, 5.0 %, 10 % & 15 % by the weight of cement. The concrete mix proportions were designed with ordinary water and Magnetized water. Neem leaves ash performing as a green rust or corrosion inhibitor. The mechanical properties of the design mix (i.e Compressive strength (CS), Spiting Tensile strength test (STS) were conducted 7 to 28 days with intervals of 7 days. 10 % replacement of neem leaves ash developed higher strength with magnetic water among the all percentages replacement. So that the 10 % replacement of neem leaves ash was concluded as optimum replacement with magnetic water.

The influence of water-gypsum ratio on the properties of national gypsum (Jοss) for various additives

In this study, an attempt has been made to investigate the influence of three additives, namely; “Tree Glue Powder (TGP)”, “Polyvinyl Acetate (PVA)”, and” Silica Fume (SF)”, on some of “National Gypsum (Jοss)” properties, namely; “Setting Time” and “Compressive Strength”. Moreover, the effect of changing “Water-Jοss” ratio (w/J) on the aforementioned properties with and without the presence of each of the aforementioned additives individually, have also been studied. For this objective, eight mixtures have been made, they were classified into two main groups in accordance with their (w/J) ratio (0.4 or 0.3), each of which was further classified into four mixtures, each of them containing one of the three aforementioned additives as well as the fourth reference mix that is free of them. The selected weighted contents of these additives were; (0.4% for TGP), (4.0% for PVA) and (0.6% for SϜ). It was found that, the compressive strength of (Jοss) have magnified when SϜ was added, but it is decreased when TGP was added. As for the setting time of (Jοss), it is decreased when SϜ was added, but it is considerably increased when TGP was added. Research results have also revealed that when the ratio of (w/J) is increased from (0.3) to (0.4), the good effect (i.e., the percentage of increasing) resulted from adding (SϜ) on the compressive strength and from the addition of (TGP) on the setting time of (Jοss) enlarged, while the bad effect (i.e., the percentage of decreasing) induced by adding (SϜ) on the setting time and by the addition of (TGP) on the compressive strength was reduced.

Investigate the Effect of Using Reclaimed Asphalt Pavement RAP and Polymer-Modified Bitumen on the Moisture Damage of Hot Mix Asphalt

Asphalt additives, in general, aim to improve the performance of asphalt mixtures by enhancing their durability and resistance to cracking and other forms of damage. Asphalt additives can be natural or synthetic, and some are biodegradable. Natural asphalt additives, such as reclaimed asphalt pavement, are much more environmentally friendly than synthetic ones. Using environmentally friendly asphalt additives can help reduce the environmental impact of the asphalt mix while enhancing its performance. This study aims to evaluate the effects of using reclaimed asphalt paving (RAP) and styrene butadiene styrene (SBS) on the performance and moisture damage of asphalt mixture, and ordinary Portland cement (OPC) was used as mineral fillers. The research includes establishing a standard reference mix for comparison and two mixtures with different quantities of reclaimed asphalt paving at percentages (15, 30, and 45%) and polymer (SBS) at 4%. The Marshall test for stability and the indirect tensile strength test were among the tests used to evaluate the mechanical properties, and the results showed that the use of reclaimed asphalt pavers and polymer-prepared bitumen led to a significant improvement in the performance of the asphalt mixture and reduced moisture damage compared to the reference mixture.

The Influence of Polypropylene Fiber and Silica Fume on the Mechanical Properties of No-Fine Concrete with Recycled Aggregate

No-Fines Concrete is a type of concrete produced without fine aggregate or sand. Because of its high porosity, it allows rainwater to seep into the ground, directly replenishing the groundwater aquifer. With a design load of three tons, no-fine concrete can be utilized as pavement for rural roads. Additionally, this type of concrete can be utilized as a sub-base material in both flexible and rigid pavements. Aside from No-Fines Concrete's permeability properties, asphalt overlays are another option. This research studied the impact of silica fume and polypropylene fiber on the properties of no-fine concrete with recycled aggregate. The ratios of cement to aggregate and water to cement were 1:4 and 0.3, respectively. The recycled aggregate was demolished reactive powder concrete used in percentages of 10, 20, and 30% as a substitution for coarse aggregate by volume. The recycled aggregate percentage of 10% was the optimal percentage as it showed the least adverse effect on the no-fine concrete mixes. The polypropylene fiber was then added to the no-fine concrete mixes with 10% recycled aggregate in the percentages of 0.5, 1, and 1.5% by volume. The optimum percentage of polypropylene fiber was 0.5%, which improved the mechanical properties of no-fine concrete. Silica fume was used as a partial substitution for cement at a percentage of 10% and added to no-fine concrete mix with 10% recycled aggregate. The results show that using 10% silica fume and 0.5% polypropylene fiber with 10% recycled aggregate increased the splitting tensile strength, flexural strength, compressive strength, and modulus of elasticity by (22.54 and 40.32%), (22.22 and 35%), (21 and 35.37%), and (22 and 38.19%) compared to reference mix (NC) and the no-fine concrete mix with 10% recycled aggregate (RNC10), respectively. In comparison, the dry density was higher by (1.34%) than RNC10 and lower by (0.68%) than NC.

New recycling technologies of demolished materials for sustainable finishes: the project of concrete reuse on site in Tres Cantos, Madrid

The work presented aims to analyse the feasibility of reusing concrete, once demolished from a building in Tres Cantos in Madrid, to manufacture finishing materials for buildings, as well as to design a procedure. The first phase consists of a bibliographic search on the reuse of materials, analysing the techniques adopted so far and the lines of work. The second phase related to the acquisition of data related to the production and recycling of Construction and Demolition Waste (CDW) at a European level. The third phase consists of the study of recycled aggregates resulting from demolitions or landslides, their treatment process. The fourth and final phase consists of the development of a laboratory test plan to evaluate varied materials for finishing exterior cement pavements with concrete from the demolition of the case study building. There were many conclusions and results of the project. The granulometry of the fine fraction of demolished concrete is suitable to produce non-structural products, such as building finishes and in particular non-driveway outdoor flooring. In terms of flexural and compressive strength, the mechanical behaviour of recycled mixes is lower than that of reference mixes. The recycled mixes show slightly higher capillary absorption capacities than the reference mixes, and the value is higher the greater the percentage of recycled aggregates used (a critical issue which can be resolved by pre-saturating the recycled material).

New recycling technologies of demolished materials for sustainable finishes: the project of concrete reuse on site in Tres Cantos, Madrid

The work presented aims to analyse the feasibility of reusing concrete, once demolished from a building in Tres Cantos in Madrid, to manufacture finishing materials for buildings, as well as to design a procedure. The first phase consists of a bibliographic search on the reuse of materials, analysing the techniques adopted so far and the lines of work. The second phase related to the acquisition of data related to the production and recycling of Construction and Demolition Waste (CDW) at a European level. The third phase consists of the study of recycled aggregates resulting from demolitions or landslides, their treatment process. The fourth and final phase consists of the development of a laboratory test plan to evaluate varied materials for finishing exterior cement pavements with concrete from the demolition of the case study building. There were many conclusions and results of the project. The granulometry of the fine fraction of demolished concrete is suitable to produce non-structural products, such as building finishes and in particular non-driveway outdoor flooring. In terms of flexural and compressive strength, the mechanical behaviour of recycled mixes is lower than that of reference mixes. The recycled mixes show slightly higher capillary absorption capacities than the reference mixes, and the value is higher the greater the percentage of recycled aggregates used (a critical issue which can be resolved by pre-saturating the recycled material).

Use of Recycled Asphalt and Waste Materials in Production of High-Performance Asphalt Mixtures

The research has been conducted to test the asphalt produced in Latvia using local mineral materials and local recycled modifiers (fiberglass, crumb rubber), as well as the recycled asphalt used in the production of high-modulus asphalt mix, which will meet the local Latvian road construction specifications and will be economically, environmentally and technically more attractive. In the theoretical part, the available sources were studied to establish a theoretical framework, assess possibilities for using recycled materials, define the concept of fiberglass, and consider its performance in asphalt mixes. During the experimental stage of the research, different asphalt mix formulas with glass fiber, crushed rubber, RAP, and other additives used to stabilize asphalt mixtures for surface and base layers were designed in the laboratory; they were compared to the reference mixes using performance tests. Then the mixtures with the best results were used in the test section of a high-intensity local road. The samples of the asphalt layers of the paved test section were tested as well. Two asphalt mixes were designed according to local Latvian road-building specifications, using fiberglass reinforcement 0.15% + 30% RAP for the base layer and crushed rubber 15% and RAP 30%+EVOFLEX CA© variable for the surface layer. The aim of the research is to offer solutions for reducing new asphalt pavement production allowing for the use of recycled asphalt mixes in local road building. The performance tests of the test asphalt mixes showed that recycled asphalt pavement fully meets the requirements of the local Latvian road-building specifications.

Assessment of the Chemical Reactivity of Brazilian Stone Cutting Plant Waste into Cementitious Matrices

The problems generated by the ornamental stone extraction and processing industry caused by the inadequate disposal of this waste can negatively affect rivers, lakes, streams, and even natural water reservoirs. This study discusses and evaluates the potentiality and challenges of dimension stone waste (DSW) recycling generated from a Brazilian dimension stone processing industry in Portland cement formulations. Cement pastes with different amounts of DSW (10–30 wt.%), quartz (10 wt.%), and calcium carbonate (10 wt.%) were prepared and characterized in the fresh and hardened states. The results showed that DSW can be used in cement formulations, and its reactivity is governed by the size of the particles. With up to 10% DSW in place of cement, the samples had greater workability and compressive strength at 28 days compared with the reference mix. However, the strength was lower at early ages (3 and 7 days). When DSW is milled, the strength of the samples containing the waste matched the reference values at all ages, and the recommended replacement limit rose to 20%. On the other hand, the particle size reduction significantly decreased the workability. The use of DSW in cement-based formulations is encouraged due to the strong presence of stone processing and cement companies in Brazil and worldwide.

Ultrasonic sensing of properties of eco-friendly cement mortar

Cement is one of the essential construction materials required to develop concrete and mortar; therefore, it is vital in developing cities' infrastructure and maintaining human civilisation. However, cement production is recognised as a major source of many environmental problems, including air and water pollution. This paper, therefore, focused on the partial replacement (from 0 to 40%) of cement in the mortars with industrial by-products and on the application of ultrasonic waves as a sensing approach to evaluate the mechanical properties of the new cement mortar. The compressive strength of the eco-friendly mortar was measured at ages of 7, 14, and 28 days, and the results showed the best compressive strength of the eco-friendly mortar was 19.8 MPa at 28 days compared to 23.9 MPa of the reference mix. Additionally, a good agreement was noticed between the ultrasonic pulse velocity (UPV) and the compressive strength confirming the applicability of the UPV for compressive strength sensing.

The mechanical properties of lightweight (volcanic pumice) concrete containing fibers with exposure to high temperatures

Abstract Fire is considered one of the main risks leading to building collapse. Lightweight concrete comprises a variety of components, each of which has a distinct behavior under the effect of temperature change. A total of 16 concrete mixtures were investigated in this article. A reference mix of concrete comprising simply ordinary Portland cement and ten mixes having varying percentages of fine and coarse lightweight aggregates (pumice), which were replaced gravel and sand by fine pumice and coarse aggregates pumice by 20, 40, 60, 80, and 100%, respectively. In addition, the study focused on the effects of adding fibers to lightweight aggregate concrete mixtures. Polypropylene fibers, carbon fibers, and steel fibers were employed as fiber additions. The binary mixture had higher density than the remaining mixtures containing one substitute. The behavior of six concrete mixes in addition to the reference mix of ordinary concrete after exposure to temperatures 100, 250, 350 and 450°C for 2 h and then cooled in two ways (water and air) as well as examined directly and the results showed that the concrete mixes containing fiber had better behavior compared to other mixtures, especially at high temperature. If left to cool in the air, the lightweight concrete containing volcanic pumice can recover its compression strength after being exposed to high temperatures.

Producing low-cost self-consolidation concrete using sustainable material

Abstract The disposal of the waste material is the main goal of this investigation by transformation to high-fineness powder and producing self-consolidation concrete (SCC) with less cost and more eco-friendly by reducing the cement weight, taking into consideration the fresh and strength properties. The reference mix design was prepared by adopting the European guide. Five waste materials (clay brick, ceramic, granite tiles, marble tiles, and thermostone blocks) were converted to high-fine particle size distribution and then used as 5, 10, and 15% weight replacements of cement. The improvement in strength properties is more significant when using clay bricks compared to other activated waste ceramics and granite tiles. The percentage increases to 11.59% at 28 days for compressive strength when using 10% replacement of cement weight. The ability to produce eco-SCC with less cement content and lower cost consumption is encouraged, although the enhancement in strength is not high since the waste can be disposable. While the percentage reduction in the strength of SCC mixes containing marble tile or thermostone block powder increases with the replacement of cement weight with a greater need for superplasticizer justification, we recommend using 5% as a replacement by weight of cement with an insignificant retardation of strength. Finally, there is a good relationship between compressive strength and ultrasonic pulse velocity and between tensile and flexural strength with a high R 2.

The effect of a starch-based stabilizing admixture on a change in the consistency of a concrete mix

Abstract: The article presents the research results into the influence of the content of a chemical-based stabilizing admixture in the form of starch on the change in the consistency of the concrete mix. The assessment of the impact of the stabilizing admixture dosed in the amount of 0.2%, 0.4%, and 0.6% in relation to the mass of cement on the change in consistency was made based on the cone drop test according to PN-EN 12350-2:2019-07. From the prepared concrete mixes, samples were also made for testing concrete density according to PN-EN 12390-7:2019-08 and compressive strength according to PN-EN 12390- 3:2019-07. For the developed composition of the concrete mix, a standard (reference) mix was prepared, which was used to compare the test results from samples containing admixture in different amounts. Based on the tests carried out, it was found that the applied stabilizing admixture based on starch with a different percentage share concerning the mass of cement significantly reduces the consistency. The use of an admixture in the case of a concrete mix with too high consistency gives the possibility of changing its purpose without affecting the other parameters. Keywords: Concrete mix; Starch; Concrete consistency